A study finds more than 80 percent of urban dwellers are exposed to alarmingly high levels of air pollution, responsible for an estimated seven million premature deaths every year. This latest report on urban air quality by the World Health Organization finds those most affected live in the world’s poorest cities.

The study finds urban air pollution has nearly doubled over the past two years in 3,000 cities in 103 countries.

It notes a whopping 98 percent of cities in poorer countries with more than 100,000 inhabitants are exposed to air pollution levels above those recommended by the WHO. That figure decreases to 56 percent in richer countries.

The WHO warns declining urban air quality is increasing the risk of stroke, heart disease, lung cancer, and chronic and acute respiratory diseases, including asthma. But, WHO Director of Public Health and Environmental Policy Maria Neira said, effective action can be taken to improve air quality, thus preventing disease and death.

“You will see that in those cities where measures have been put in place, you can see a decrease on the levels of air pollution and, therefore, on the health risks caused by air pollution,” said Neira.

The study finds that death caused by particulate matter, such as sulfate, nitrates and black carbon could be lessened by 15 percent by reducing the air pollutants.

Coordinator of WHO’s Department of Public Health and Environmental Policy, Carlos Dora, said even the poorest cities can improve their air quality by employing affordable strategies including the use of renewable power sources, such as solar and wind, and sustainable public transportation.

“If you have clean transportation means, like cycling, walking or rapid transit systems, where you have a lot of people being carried with a few vehicles, then you have less air pollution. Or, if you have cities like New York, which have cleaned the fuel to heat and cool the buildings in a major way… then you have important improvements in air pollution,” said Dora.

The report found cities and towns that have the poorest air quality are in the Eastern Mediterranean and South East Asian regions, followed by countries in Africa.